A straight line has the equation $y = 2x - 1$ - OCR - GCSE Maths - Question 21 - 2021 - Paper 3
Question 21
A straight line has the equation $y = 2x - 1$.
Write down the gradient of the line.
Here are the equations of four straight lines.
$y = 2x + 3$
$y = 1 - x$
$y... show full transcript
Worked Solution & Example Answer:A straight line has the equation $y = 2x - 1$ - OCR - GCSE Maths - Question 21 - 2021 - Paper 3
Step 1
Write down the gradient of the line.
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Answer
The gradient of the line y=2x−1 is the coefficient of x, which is 2.
Step 2
Which of the four straight lines is parallel to $y = 2x - 1$?
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Answer
The line that is parallel to y=2x−1 must have the same gradient. Therefore, the line y=2x+3 is parallel to it, as both have a gradient of 2.
Step 3
Explain why the student is wrong.
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Answer
The steepness of a straight line is determined by its gradient, not the constant term added. The gradient of the line y=21x+4 is 21, which is less steep than the gradient of 2 from y=2x−1. Hence, y=21x+4 is not the steepest line, despite having a larger constant.
